Disk bit



Feb. 7', 1933. H. W. FLETCHER E-r AL 1,896,297

DISK BIT Filed March 22, 1930 Patented Feb. 7, 1933 UNITED STATES PATE Nr OFFICE HAROLD w. FLETCHER AND FLOYD L. SCOTT, or HOUSTON, TEXAS, ASSIGNORS To .Y

HUGHES TOOL COMPANY, or HOUSTON, TEXAS, A CORPORATION oRTRxAs DISK ,RIT

Appnation mea March 22, 1930. serial No. 437,953.

We contemplate the provision of a straight shaft but with bushings thereon, arranged in oifset relation to get the desired offset position on the drill of the separate cutters.

In the drawing herewith wherein we have shown earth boring drills equipped according to our invention, Fig. l is a side elevation v of a disk bit embodying the invention.

Fig. 2 is a transverse section on the plane 2-2 of Fig. 1.

Fig. 8 is a Side elevation of a drill equipped with cutters mounted according to our invention an-d illustrating a slightly different embodiment of the said invention, the upper part of the drill being in central vertical section.

Fig. 4 is a transverse section on the plane 4 4 of Fig. 3.

In carrying out the invention we have 1llustrated a drill bit of the usual construction having an approximately cylindrical head l, the upper end of which is reduced in diameter and threaded at 2 for engagement with the drill collar. The head 1 has a pair of downwardly extending legs 3, the lower ends of which form a support for the disk shaped cutters 4.

As will be seen from the drawing, the drill therethrough for the flushing fluid which is adapted to conduct the flushing Huid directly upon the cutters.

In Figs. 1 and 2 we have shown the legs 3 of the cutters olfset slightly relative to each other, one leg being slightly to one side of the central axis of the bit, and the other leg being offset to the opposite side of the said axis. The inner faces 6 of the legs are flattened and these flattened faces are parallel with each other to furnish a lateral support for the bushings 7 upon which the cutters are mounted. Each leg has adjacent the lower end an opening 8 therein to receive the shaft 9. This opening is countersunlz at 10 at its outer end to receive a washer 11 through which the end of the shaft may project.

The Shaft 9 is cylindrical and extends through the legs of the cutters in a line cutting the plane inner faces of the legs at an angle not perpendicular thereto, so as to ob- `is desirable.

tain the oli'set mounting of the cutters which The ends ofthe shaft are reduced in diameter at 12 to engage within the a radialflange 13' to bear against the inner face of the leg. Said bushing is adapted to be held in non-rotatable position on the `shaft by means of a. set-screw l4'extending through the leg andengaging' within a recess in the bushing. vEach bushing is .set at an angle to the shaftuponwhich it is mounted by forming a shaft-receiving opening 15 therein, extending in a slightly diagonal line through the bushing,.said opening thereby being a linenot truly along the axis of the bushing. T his shaft-receiving opening is thusv formed so that ythe cutters 4 may be `parallel with Vveach other,V and yet set in the head of the bit ina positionolfset from each other, as 'will be understood from Fig. 2.

p The cutters are beveled at 16 on their outer faces, the forward-faces '17 thereof. being flattened toward the cutting edge to present a cutting edge. along ,the forward side thereof.

There is a' hub 1S on each cutter extended inwardly so as to partially protect `the shaft 9 from the action of the flushing fluid.

ln Figs.' 3 and 4 we have obtained the offset arrangement ofthe cut-ters in a slightly different type of head. The legs .3 in this cutter are arranged directly opposite to each other.

the innerfaces 6 being parallel and oppositely arranged. v The'shaft 9 extends through the. legs of the cutter in a, line perpendicular to the inner faces, said shaft being otherwise held inpositon in the same manner as in the iirst embodiment.

In this arrangement, however, the bushings 7' are formed with the outer flanged end 13 of approximately wedge shape, one side being thicker than the other, thus placing Vthe cutters 4 in a position to offset from each other.

The openings through the bushings to receive the shaft are in the same diagonal position relative to the cutters as is the case in Fig. 2.

5 In other respects the two arrangements are approximately the same. TheY cutters are mounted on the bushings in the same manner parallel with each other, and rotated onthe bushings supported on the shaft and held in 10 position by cap-screws 14.

The advantages of the construction lie in the fact that we are enabled to mount the cutters upon a straight cylindrical shaft supported at both ends in the legs of the bit.

l5 The cutters are adapted to rotate smoothly on their bushings and in an offset position as is desired. The strength of the structure is materially increased, and the cost of construc; tion is also cheapened so that we arev enabled 29 to supply a bit of this character at a price within the means of the ordinary operator.

`What we claim as new is:

1. A drill bitincluding a head, two opposed supports thereon, a straight cutter 2D shaft supported at its ends in said supports,

bushings secured non-rotatably on said shaft,

and cutters mounted on said bushings, said bushings being formed with diagonal shaftreceiving openings to position the cutters in i3 offset relation, whereby one will contact with the wall of the hole at one side only and the other at the opposite side only.

2. A drill bit including a head, two spaced Y downwardly extending legs thereon, the in- L# ner opposed faces thereof being flattened,

bushings having heads thereon fitting against said faces, the inner ends of said bushings being spaced slightly apart, said legs and bushings having aligned openings diagonally 9 through said bushings, a straight shaft through said openings, means securing the heads of said bushings to said legs, and cutters rotatable on said bushings and offset lat- 4 erally on opposite sides'of said shaft.

4b 3. A drill bit including a head, two spaced A(ilownwardly extending legs thereon, the inner opposed faces thereof being flattened, bushings having heads thereon fitting against n said faces, the inner ends of said bushings W being spaced slightly apart, said legs and bushings having aligned openings diagonally through said bushings, a straight shaft through said openings, means securing the heads of said bushings to said legs, disk d shaped cutters rotatable on said bushings, said cutters bearing against the heads of said bushings on one face of each cutter and hubs on the adjacent faces of said cutters flush with the inner ends of said bushings. 50 In testimony whereof, We hereunto ailiX our signatures, this the 12th day of March, A. D., 1930. Y

HAROLD W. FLETCHER. FLOYD L. SCOTT. 

